CN1281182C - Thermokeratoplasty system with power supply that can determine wet or dry cornea - Google Patents

Abstract

A power supply for a thermokeratoplasty system. The power supply can be connected to an electrode and a return element that are both coupled to a cornea. The power supply can perform a test routine to determine whether the cornea is too ''wet'' or too ''dry''.

Description

Thermokeratoplasty system with the power supply that can determine wet or dry cornea

Background of invention

1. invention field

The present invention relates to a kind of thermokeratoplasty probe, it places direct contact outer corneal surface.

2. prior art

The technology that is used to correct defects of vision comprises the orthopedic of cornea.For example, Jin Shi state can be corrected by cut out some little otch in the film of cornea.These otch can make the film diastole of cornea and increase the radius of cornea.Usually utilize laser or accurate pocket knife to produce these otch.Be used to produce that otch is referred to as radial keratotomy usually with this operation of the defective of myopia correction and be well-known in the art.

Present radial keratotomy generally makes otch penetrate about 95% cornea.Cornea is penetrated into such degree of depth and has increased the danger that stabs out demours' membrane and endodermis, and causes the permanent damage of eye.

In addition, the light that enters cornea is reflected and produces glare effect at otch sight line place in the visual field by the otch spot.The glare effect of this spot has weakened patient's night vision.The very ideal operation that should provide a kind of myopia correction makes it not need 95% penetrance of cornea.

Radially the keratotomy technology is effective to myopia correction only.Radial keratotomy can not be used to correct for example eye state of hypermetropia.In addition, keratotomy reduce or astigmatism aspect have limited application.The patient's of hypermetropia cornea is more flat (big spherical radius).One flat cornea forms a lens combination, and it also makes video focus on the retina of eye improperly.Hypermetropia can be by reducing cornea orthopedic rectification of eye of spherical radius.Find, by heating and making the regional area degeneration of eye can correct hypermetropia.Denatured tissue contracts, the shape that changes cornea and the optical characteristics of corrective ophthalmic.The film of this heating cornea is referred to as thermokeratoplasty usually with the operation of rectification patient's vision.

Authorize No. 4461294, the United States Patent (USP) of Baron, No. 4976709, the United States Patent (USP) and the open text WO 90/12618 of PCT that authorize Sand all disclose the thermokeratoplasty technology, and it utilizes the LASER HEATING cornea.Laser energy absorption by photon in corneal stroma produces partial heating., the matrix areas of heating changes the shape of eye so shrinking.

Though is effective at eye aspect orthopedic, be expensive in system's manufacturing based on laser of Baron, Sand and PCT file, has uneven conductive characteristic, not to limit automatically, eye is easy to form too much heat, the damage that may cause astigmatism and produce over-drastic adjacent tissue, and need the secular stable of eye.Expensive laser systems has improved the cost of operation and can not obtain market acceptance widely and application economically.In addition, LASER HEAT ceratoplasty technology is shunk substrate unevenly and is not shunk cornea cornea Descemet (Bowmanslayer).Shrink substrate and when not having corresponding contractions of cornea cornea Descemet, can the generation mechanical strain in cornea.This mechanical strain may produce reshaping of unwanted cornea and when the infringement healing of cornea visual acuity corrected disappears.Laser technology also may be worn out cornea cornea Descemet and stay corneal leukoma in the visual field of eye.

The United States Patent (USP) of authorizing people such as Doss discloses for No. 4326529 and No. 4381007 in order to heat big cornea zone so that the electrode of myopia correction.Positioning of electrode is in a housing, and housing separates the top of electrode with the eye surface.Isotropic saline solution is aspirated by electrode washing and by a passage that forms between the inner surface of electrode outer surface and cover.Saline solution forms a conducting medium between the film of electrode and cornea.Come the skin of the current flow heats cornea of self-electrode.The heating exterior ocular makes cornea be shrunk to a new radiation shape when organizing.Saline solution also plays coolant, and it cools off outer epithelial layer.

The saline solution of DossShi device is diffused in bigger cornea district to the electric current of electrode.Therefore, the thermokeratoplasty technology of employing DossShi device is subject to and has orthopedic cornea bigger and nonconforming denatured areas in the optical axis of eye.The electrode assembly of DossShi system is more complicated and be not easy to use also.

People's such as Doss " a kind of technology that is used for selectivity heating corneal stroma " is stated from " contact and intraocular lens medical journals " (Contact ﹠amp; Intraoccular Lens MedicalJrl.) the 6th volume the 1st phase 13-17 page or leaf, discussed a kind of method to March in January, 1980, and wherein the patent cyclic salt electrode (CSE) of Doss is used to heat a primary cornea (PigCornea).Electrode provides the electric power of 30 volts of virtual values in 4 seconds.The result shows that substrate is heated to 70 ℃ and cornea cornea Descemet is heated to 45 ℃, is lower than 50-55 ℃ temperature will shrinking cornea and don't disappear and need.

" necessity of the research of current expection " of McDonnellShi is stated from " refraction and cornea surgery (Refractive; Corneal Surgery) " the 5th volume in January/February, 1989, has been discussed and has been utilized the thermokeratoplasty technology to carry out the orthopedic advantage of cornea.This article has been discussed a kind of method, and the collagen that wherein utilizes rf wave heating substrate is with the rectification as cornea posterior staphyloma state.Report that as this article patient has eye that initial extreme flattens succeeded by disappearing significantly in several weeks in method.

People's such as Feldman " in the later extinction effect of people's radially thermokeratoplasty " is stated from " refraction and cornea surgery " the 5th volume, in JIUYUE/October, 1989, another kind of thermokeratoplasty technology has been discussed in order to correct hypermetropia.Feldman inserts a probe at four different positions of cornea.Probe is heated to 600 ℃ and insert 0.3 second of cornea.As the method for discussing at the article of McDonnell, the Feldman technology has reduced hypermetropia at first, but patient has significantly and disappears in 9 months of formality.So far, the result of study of delivering about the thermokeratoplasty technology not makes it can conclude orthopedic and correct the vision of cornea and do not have disappearing significantly of corneal correction.

Therefore it is desirable to very much provide a kind of thermokeratoplasty technology, it can be concluded the vision of orthopedic and corrective ophthalmic and not have that visual acuity is corrigent to disappear significantly.

It is desirable to very much to will be appreciated that in the situation of implementing before the electric heating ceratoplasty method between the electrode and cornea that electrically contacts.The cornea of overdrying can form high electrical impedance and make the relatively large local heat of generation in tissue.Cross wet cornea meeting scattered current to cause cornea tissue degeneration fully.Very ideal a kind of power supply and the technology of should providing makes its state that can test eye so that whether decision has satisfied circuit passband.

Summary of the invention

The present invention includes a kind of power supply that is used for the thermokeratoplasty system.This power supply can be connected on an electrode and the loop element, and both all are connected in cornea the back.This power supply can realize test program with the decision cornea be " wetting " or " doing ".

The accompanying drawing summary

Fig. 1 is the perspective view of the electrode system of thermokeratoplasty of the present invention;

Fig. 1 a offers the oscillogram of the probe of system for demonstration;

Fig. 1 b is for showing the typical vision correction spirogram that disappears in time;

Fig. 1 c is the image of the heat distribution of the nominal that produced by electrode system of the present invention in cornea;

Fig. 2 is the vertical view of the electrode catheter of system;

Fig. 3 is the side view of the probe among Fig. 2;

Fig. 4 is the enlarged drawing of probe tip;

Fig. 5 is used for the treatment of the side view of probe of the diaphragm area of cornea for expression;

Fig. 6 is the vertical view of the pattern of the denatured areas of expression cornea;

Fig. 7 is the perspective view of another embodiment of probe;

Fig. 8 a～b is for realizing method of operating of the present invention;

Fig. 9 represents the pattern as the zone of the otch of myopia correction state and degeneration;

Figure 10 represents another pattern as otch and zone degeneration of correcting the hypermetropia state;

Figure 11 represents a preferred side of implementing of the present invention;

Figure 11 a is the enlarged drawing of the tip of Figure 11;

Figure 12 is the perspective view that has as the probe of the loop electrode of eye speculum, and eye speculum keeps eyelid to be in open position;

Figure 13 is the side view of the embodiment of another probe tip;

Figure 14 is the side view of the embodiment of another probe tip;

Figure 15 is the side view of the embodiment of another probe tip;

Figure 16 is the side view of the embodiment of another probe tip;

Figure 17 is the side view of the embodiment of another probe tip;

Figure 18 is the side view of another probe embodiments;

Figure 19 surpasses the circuit diagram of the useful life use probe of regulation for restriction;

Figure 20 is the side view of another probe tip structure;

Figure 21 is the amplification view of probe tip;

Figure 22 is the enlarged drawing of the probe tip of insertion cornea;

Figure 23 is the side view of another embodiment of electrode;

Figure 24 is the side view of another embodiment of electrode;

Figure 25 is the side view of another embodiment of electrode;

Figure 26 is the sketch map of the embodiment of power supply;

Figure 27 is the flow chart of expression power operation;

Figure 28 a～j is the end view of another embodiment of electrode;

Figure 29 is the cutaway view of another embodiment of probe assembly;

Figure 30 is the cutaway view of the probe retainer of the probe that is used for installing shown in Figure 29;

Figure 31 is the cutaway view of another embodiment of probe assembly;

Figure 32 is the amplification view of the probe that installs shown in Figure 31;

Figure 33 is the cutaway view of another embodiment of probe assembly;

Figure 34 is used for the side view of another embodiment of the handpiece of probe assembly for expression.

Preferred embodiment describes in detail

With reference to all accompanying drawings that particularly have label, Fig. 1 illustrates hotceratoplasty electrode system 10 of the present invention.Thissystem 10 comprises that one is connected in theelectrode catheter 12 of a power subsystem 14.Power subsystem 14 comprises a power supply, and it givesprobe 12 with power transmission.Probe 12 has ahandpiece 16 and a probe electrode is connected in thelead 18 ofplug 20, thecooperation socket 22 that plug 20 inserts on thefront panel 24 that is positioned at power subsystem.Handpiece 16 can be constituted and is approximate 0.5 inch diameter and 5 inches long by dielectric material.

Power supply 14 provides the energy of scheduled volume by the application of electric power controlled in the persistent period of aregulation.Power supply 14 can have manual controller, and it makes user can select each processing parameter for example power and persistentperiod.Power supply 14 also can constitute provides automaticoperation.Power supply 14 can have monitor and feedback system, in order to measurement tissue impedance, tissue temperature and other parameter, and regulates the result of the output of power supply with the realization requirement.This device can also have a display can be used for the residue application ofprobe 12 in order to indication number.

In this preferred embodiment, power supply provides constant current source and voltage limit to prevent to produce electric arc.In order to protect patient with anti-overvoltage and overpower,power subsystem 14 can have upper voltage limit and/or Upper Bound Power, stops leading to the electric power of probe when unit output voltage or power surpass asetting.Power subsystem 14 also can comprise monitor and warning circuit, and the resistance of its monitoring load or impedance are also sent alarm signal when resistance surpasses and/or be lower than the limit of regulation.Alarm device can send or sound sensation signal and/or visual signal inform that resistance has surpassed outside specified limits to user.In addition, this power subsystem can comprise an earth-fault indicator, and/or the temperature monitoring of a tissue.The front panel of power subsystem generally includes quantifier and display, so that the indication of the power that flows to probe, frequency etc. to be provided.

Power subsystem 14 can be carried a horsepower output in the frequency range of 5KHz-50MHz.In this preferred embodiment, power offers probe with the frequency in the 500KHz scope.Thisunit 14 is designed to make the power of supplying withprobe 12 and be no more than 1.2 watts.Electric power to persistent period that applies each time at a specific cornea position generally at 0.1-1.0 between second.Thisunit 14 is preferably set to the power of carrying about 0.75W and continued for 0.75 second.Fig. 1 a illustrates a typical voltage waveform that is applied by unit 14.Each pulse of the electric energy of being carried byunit 14 is the signal of a height damping, and its maximum coefficient (peak voltage/active voltage) was greater than 10: 1 usually.Realize the diffusion of each electric power with a repetitive rate.Repetitive rate can the scope between 4-12KHz in and preferably set at 8KHz.

This system has a switch imposes onprobe 12 with control electricpower.Power subsystem 14 also comprises a timer circuit, so that electric power can impose onprobe 12 in an accurate official hour interval.Timer can be consumption timer or other similarly traditional Circuits System so that stop giving the electric power of probe after at interval at official hour.This unit also makes user can apply electric power till cut-off switch.In an embodiment, power supply can be a unit of being sold by BirtcherMedical company, its trade mark is called HYFRECATOR PLUS, model 7-797, and this unit is modified to has voltage, waveform, persistent period and the power limit that meets above-mentioned specification requirement.

Power subsystem 14 can have acontrol element 26 so that user can be selected between operation " one pole " or " bipolar ".Power subsystem 14 can constitute the setting of the numeral that a single scope is provided, thus, and by hardware and software decision appropriate output power, persistent period and the repetitive rate of device.The front panel of power subsystem can also have the control unit (not shown), so that the surgeon can change unitary power, frequency, timer interval etc.The loop electrode (not shown) that is used for unipolar probe can be connected in power subsystem by the joint on the unit.Loop electrode is preferably a cylindrical bar by patient's gripping, or a glance localizing electrode.

Find, when higher diopter, can obtain effective result by two different using are provided at same position.Being listed in the table below, (power setting d) (peak power) and persistent period are set, and wherein position (Loc) is the number of denatured areas in the cornea and number of times that dots/Loc uses for each position power for the different dioptric rectification that is used among the I.

Table I
					-d	Count/position	The position	Power (W)	Time (second)
1.5	1	8	0.66	0.75
					2.5	2	8	0.66	0.75
3.5	2	8	0.83	0.75
					4.5	2	16	0.66	0.75
6.0	2	16	0.83	0.75

Adopt cited all parameters in the Table I, on 36 different patients, finished operational approach of the present invention with hypermetropia to a certain degree.Produced the pattern of a 8-16 denatured areas in the non-visual zone of eye.The patient that the high power treatment needs higher diopter correction is used in utilization.Fig. 1 b illustrates the amount of disappearing in the eye vision rectification.Eye passes through initial excessive rectification to compensate disappearing in the known operational approach.As shown in Fig. 1 b, disappearing became stable later on and was later on completely stable at 180 days at about 60 days.Excessive corrigent error is in+/-0.5 diopter.

Fig. 1 c illustrates the heat distribution of the nominal that is produced by the electric power that applies to cornea.Known as those skilled in the art, cornea comprises a demours' membrane and an endodermis behind an epithelial layer, a cornea cornea Descemet, a substrate, the cornea.Under the situation of the scope that does not limit this patent, the applicant provides following discussion with regard to this method to the possible effect of cornea.When initial when electric power is imposed on cornea electric current flow through the center of direct tissue in abutting connection with probe tip.The internal resistance heating that the applying of electric power causes cornea and the dehydration of tissue.The dehydration of tissue increases the impedance in local heat zone rapidly, and wherein power supply flows in the outside mode shown in the letter head among Fig. 1 c.Dehydration and outside mobile cycle of electric current last till always that the resistance of the outer peripheral and whole heat distribution from the tip to the anterior corneal surface is high enough to stop the current flow of continuation and the degeneration that further do not cause cornea tissue.Probe produces a heat distribution according to the specific power/time set of power supply with direct contact of cornea, and it makes cornea cornea Descemet and the equal degeneration of substrate.The degeneration of the circular pattern of cornea cornea Descemet and substrate produces one and is connected the annulus that belt is shunk.This annulus will make the cornea steepening and the focusing of the mirror image on the retina is come to a point.In order to control and to reduce the zone of degeneration as far as possible, by apply ointment or plaster dry swab or cross that the eye surface dries up dry air or nitrogen keeps the drying on eye surface to cornea.

The amount of penetrating of the high resistance corneal of the design of power supply and denatured areas and the zone of degeneration provide a self limit.In case stood degeneration, thereby cornea forms the zone that the low electric current of measuring of a high impedance flows through degeneration to any follow-up electric power that applies.Find that method of the present invention has a degeneration profile that roughly is not more than 75% self-limiting of the substrate degree of depth.This prevents can be down to demours' membrane behind the cornea and endodermis when the surgeon from making the eyes degeneration.

Fig. 1 c illustrates respectively right-1.5d ,-2.5-3.5d and-heat distribution of the nominal of the diopter correction of 4.0-6.0d.According to Table I ,-1.5d diopter correction produces one and is about the denatured diameter of 1mm and stroma penetration is about 30%.-2.5-3.5d correct to produce the diameter that is about 1.13mm of a degeneration and stroma penetration is about 50%.-4.0-6.0d correct to produce the diameter that is about 1.25mm of a degeneration and stroma penetration is about 75%.

Fig. 2-5 illustrates an embodiment of probe 12.Probe 12 has onefirst electrode 30 and one second electrode 32.Though described and shown two electrodes, should be appreciated that probe can have two electrodes (bipolar) or have only first electrode (unipolar).If adopt a unipolar probe, be connected in patient usually or grip a loop electrode (neutral electrode) to be provided for one " loop " of electrode current by it.

Twoelectrodes 30 and 32 stretch out fromhandpiece 16, and handpiece comprises the insulatingconductor 34 of a pair of inside, the near-end of its contactelectrode.First electrode 30 has atip 36, and it stretches out from onefirst spring element 38, and this spring element stretches out fromhandpiece 16cantilevers.Electrode 30 is that the phosphor bronze of 0.2-1.5mm or saturating steel steel wire or pipe constitute by diameter preferably.It is long that thespring section 38 offirst electrode 30 is preferably 50 millimeters (mm).In one embodiment,tip 36 has the angle between 15-60 °, nominal be 30 °, and the pinnacle radius is about 50 microns.The major part ofelectrode 30 is coated with insulating material in case produce electric arc, and protects non-destination organization, user and patient.The less spring force of probe provides enough electrode pressures and does not penetrate cornea.

Second electrode 32 comprises adisc portion 40, and it stretches out from onesecond spring element 42, and this spring element also stretches out fromhandpiece 16 cantilevers.The distance that thedisc portion 40 andfirst electrode 30 spaced apart are predetermined and have one withtip 36 are concentric perforates 44.In this preferred embodiment, the external diameter ofdisc portion 40 is that 5.5mm and aperture are 3.0mm.Dish 40 basal surfaces that also have the shape that accords with cornea or sclera substantially of a spill.

In one embodiment, the spherical radius and ofbasal surface 46 with an about 12.75mm helps the localized grip surface of eye.Second electrode 32 provides a loop for the electric current from first electrode 30.In order to guarantee the proper grounding of cornea, the surface area ofdish 40 usually than the big 20-500 of contact area oftip 36 doubly.In this embodiment preferred, second spring element, 42 formations have the spring constant less than half of the rigidity offirst spring element 38, so thatsecond electrode 32 will have the bigger amount of deflection of per unit power than first electrode 30.As shown in Figure 3,tip 36 anddish 40 are usually located at angle a ' and a " to locate, it can be 45 ° in this preferred embodiment in the scope between 30 °-180 °.As shown in Figure 5,probe 12 is pushed down cornea so thatsecond electrode 32 can be with respect to 30 deflections of firstelectrode.Second electrode 32 deflects into till the 36 contact corneas of tip always.

For would rather " with two handss " surgeon of operation, probe can constitute two, one is first electrode, and another part is second electrode, it also makes eyes stable in case the cornea motion.Though describe and show the situation of probe degeneration cornea, should be appreciated that probe of the present invention and method can be used for its hetero-organization of degeneration with the rectification as wrinkle, incontinence etc.For example, probe can be used to shrink sphincter with the rectification as incontinence.This technology can be the same with forming a line of tightening, band or cylindrical many points that closely separates basically.

Fig. 6 illustrates a pattern in the zone 50 of degeneration, and it is with correcting the hypermetropia state.Outer peripheral in the optical axis part 52 of eye producescircle youngster 8 or 16 denatured areas 50 around the center of cornea.The optical axis has about 5 millimeters nominal diameter.Found that according to thisoperation 16 denatured areas reach the contraction of maximum cornea and littler postoperative astigmatic effect.Usually between 6-8mm, its preferred diameter is about 7mm to the diameter of circular denatured areas.If first lap does not have correction ocular effectively, then can repeat same pattern, or can or become delegation or stack ground to produce another pattern of 8 denatured areas in the circle of about 6.0-6.5mm diameter.Found that the hypermetropia state of overcorrection can be coated to denatured areas by continuous 2 weeks in postoperative 4 days and after formality with a kind of steroid such as cortisone can offset and reach 80%.Therefore after 30 days the phase of waiting, can repeat method of the present invention.

The definite diameter of pattern is people and different due to illness, should be appreciated that, the point of degeneration should be preferably formed in the not visible part 52 of eye.Though the pattern of a circle is shown, should be appreciated that the zone of degeneration can be positioned at any position and be any pattern.Except that being used as the rectification of hypermetropia, the present invention can be used for the state of astigmatism.For the state of astigmatism, the zone of degeneration is created in scattered-light flat the tip of the axis usually.The present invention also can be used to correct radially keratotomy method, and this method is as the situation of the overcorrection of the state of a myopia.

Probe and the power setting of having found to be used to produce the zone of degeneration do not arrive the back demours' membrane.The denatured areas of having found the cornea Descemet in the visual field can hinder patient's the visual field, particularly at night.The present invention stays a spot, and its 6 menstruation slit lamp examinations after operation almost are invisible.Found not produce because the celestial body effect of light by causing as the refraction in the crack that produces in the keratotomy radially in corrigent method by the denatured areas that the present invention produces.

Fig. 7 illustrates another embodiment ofprobe 60, and it has a plurality offirst electrodes 62 that are connected in a support 64.Support 64 comprises one by eachdistance piece 70 and second ring, 68 isolating first rings 66.Support 64 can be connected on leader's (not shown), and it makes the surgeon can more easily useprobe 60.

The perforate 72 thatfirst electrode 62 passes in thering 66 and 68 is extended.Electrode 62 can move with respect to support 64 along the direction shown in thearrow.Probe 60 has a plurality of between each ring and be placed inspring 74 on thepacking ring 76 that is installed on electrode 62.Spring 74 is biased into the position shown in Fig. 7 with electrode 62.In this preferred embodiment,probe 60 comprises with a diameter being 8 electrodes of 7.0 millimeters circular, fashion setting.

In operation,probe 60 is pressed on the cornea andelectrode 62 is moved with respect to support 64, produce minimum counter-force organizationally thereby the spring constant ofspring 74 is lower.Electric current is supplied withelectrode 62 by thelead 78 that is connected on theelectrode.Probe 60 is preferably used as unipolar device, and wherein electric current flows through tissue and flows into and is connected in patient or by a loop electrode of its gripping.Perhaps, probe 60 can be bipolar, and one of them or more a plurality ofelectrode 62 can provide electric power and other electrode can provide an earth-return circuit.Probe 60 can be designed so that the diameter of arrangement of electrodes is adjustable.Arrangement of electrodes can be by changing between 5.5,6.0,6.5,7.0,7.5,8.0 and 8.5 millimeters with increasing.

Fig. 8 a and 8b illustrate a preferred corrigent method as the hypermetropia state that adopts electrode system of the present invention.Refractive reading in operating block 100 is to have and do not have subsequently initial generation of eyes that corpus ciliare is shaped as shown therein.In operating block 102, record the pressure of ophthalmic with a piezometer and pachometer respectively and at the corneal thickness at the center of eye.If the pressure of ophthalmic is 20mm Hg (mercury column) or bigger, in order to reduce intra-ocular pressure (I.O.P), to be coated on the cornea with 1 0.5% solution that trade (brand) name " Betagan " is sold, one day twice coating 2-3 month, repeat initial test then, in operating block 104, obtain the shape of the pattern reading of eye then with the decision cornea.

Applying electrode withprecontract 30 minutes, in operating block 106, give patient with light tranquilizer stable (medicine) (trade (brand) name Valium), and the surgeon use drop as 5 milligrams (mg), the drop of selling with trade (brand) name " Madryacil " for example is so that expansion pupil and freezing adjusting eyes.In operating block 108, before this operation, use 2 partial cocaines that are referred to as " Proparacaine " usually to eyes immediately.A micro-smooth directive cornea of harmonizing is so that labelling in operating block 110.This moment, light can cross cornea along lateral.Having found provides good visuality to eyes and does not stimulate retina or its sensitization is bleached at lateral light.

In operating block 112, the surgeon is labelling 8 or 16 points on cornea, and wherein this pattern has the diameter of a preferred about 7mm.The surgeon adjusts to suitable setting with the power and the setting of persistent period of power subsystem.In operating block 114, the surgeon is placed on the foot switch of a some mark and press down system with probe tip then, so that give probe with electric power, repeated transmission is gone into cornea.Repeat this process in whole some mark.The epithelial layer of in operating block 116, getting rid of denatured areas then with a spatula.If desired-2.5-3.5d or-diopter correction of 4.0-6.0d, then once more probe tip is placed to contact with each point and apply electric power so that produce darker heat distribution in the substrate to cornea.Utilize an automatic refractor to check this operation then.In operating block 118, eyes cover with retaining cloth or a black glass, and give patient's medication, and patient preferably takes a kind of medicine that antibiotics is for example sold with trade (brand) name " Tobrex ", take once in per 2 hours in 48 hours, then 5 day every day 3 times.Patient also preferably takes oral analgesic, and for example a kind of medicine of selling with trade (brand) name " Dolac " was taken 10mg in per 8 hours in 48 hours, and with a kind of medicine that trade (brand) name " Globaset " is sold, taken once in per 8 hours in 48 hours.If patient is overcorrection, then this operates in operation back and waits for 3-4 days and can be fallen back, and uses for example cortisone of a steroid to eyes then, and one uses 1-2 week at 3 times.

Fig. 9 illustrates the pattern of adenatured areas 130 and the mode combinations ofotch 132, in order to the state of myopia correction.This otch can be finished according to the pocket knife or the laser of traditional radially keratotomy method system.The 1mm of otch from the 3.5mm diameter to limbus of corneae is with interior about 85% the degree of depth that switches to cornea.Adopt said method between each otch 132, to form denatured areas then.It is 0.75 second that power subsystem preferably set in power and the persistent period of 0.75W.Reduce to minimum in order to make to disappear, it is important heating cornea lentamente, and found owing to patient stationkeeping ability and the reason in surgical response time to resemble 0.75 second be the preferred persistent period.Denatured areas pull otch and help the orthopedic of cornea.Found this method to diopter correction reach+10.0d is effective.Penetrate cornea only 85% rather than 95% otch of traditional keratotomy reduced to stab the danger of back demours' membrane and endodermis.This is different from traditional radially keratotomy method, and the latter can not be used as greater than 3.5 dioptric rectifications usually.

Degeneration pattern shown in Fig. 6 has shown rectifiable 7.0 diopters that reach.As shown in Figure 10, except that the pattern of eachdenatured areas 136, also can form eachotch pattern 134 of circumferential pattern, so that rectification is increased to 10.0 diopters.These otch will weaken eyes and allow the more significant orthopedic of eye.The pattern of this otch can form 6mm diameter or 8mm diameter.Otch penetrates usually and is not more than 75% of cornea.The contractility of denatured areas can form the gap in otch.Can preferably fill up this gap with collagen or other suitable materials.

Figure 11 illustrates another embodiment of probe, and it has a single electrode 140.Electrode 140 has atip 142, and its diameter is preferably 0.009 inch.Stretch out inelastic rod 144 this tip, and thisbar 144 bends to and the surgeon can be above eyebrow gas and nose be put into the top on the cornea and hinder surgical sight line.The preferably insulating and diameter ofelastic rod 144 is 0.2-1.55mm.Elastic rod 144 stretches out from abase portion 146, and the latter inserts in thehandpiece.Base portion 146 preferably is made of rustless steel and its diameter is the 0.030-0.125 inch, and preferred diameter is the 0.060-0.095 inch.

As shown in Figure 11 a, the end oftip 142 is preferably planar and have a grain surface 148.Thisgrain surface 148 catch cornea slightly so that when applying electric power to eye this tip can not move apart gauge point.

As shown in Figure 12,probe 200 has a loopelectrode eye speculum 202, and it keeps eyelid to be in openposition.Eye speculum 202 has a pair ofcup 204 that is positioned at the end of steel wire 206.The position that eachglass 204 is placed on the following of eyelid and keeps eyelid in the process of operation.What stretch out fromeye speculum 202 is asteel wire 208, and it inserts in " loop " adapter ofunit 14 usually.Find that method of the present invention will produce more consistent result when probe is used as loop electrode with eye speculum 202.Since betweeneye speculum 202 and theprobe 200 than short distance and the wet interface between cornea andeye speculum 202, the impedance route betweenprobe 200 andeye speculum 202 is relatively more coherent.

Figure 13-15 illustrates the embodiment of other probe tips.Each tip has ladder, and it increases the electric current density at corneal interface place.Each top preferably is made of rustless steel, the shape shown in it is configuredas.Tip 220 shown in Figure 13 has thecylindrical ladder 222 that stretches out from base portion 224.Ladder 222 terminates in an end points, but should be appreciated that the end ofladder 222 can have a plane surface.In the preferred embodiment, the diameter ofbase portion 224 is 350 microns (μ m), and the diameter ofladder 222 is 190 microns and length is 210 microns.

Tip shown in Figure 14 230 hasfirst ladder 232 that stretches out frombase portion 234 andsecond ladder 236 that stretches out from first ladder 232.The end ofsecond ladder 236 can have texture to improve contacting between probe and the cornea.In this preferred embodiment, the diameter offirst ladder 232 is 263 microns and length is 425 microns, and the diameter ofsecond ladder 236 is 160 microns and length is 150microns.Tip 240 shown in Figure 15 hasfirst ladder 242 that stretches out frombase portion 244 and thesecond taper ladder 246 that stretches out from first ladder 242.In this preferred embodiment, the diameter offirst ladder 242 is 290 microns and length is 950 microns.The diameter ofsecond ladder 246 is 150 microns, and length is that 94 microns and a radius are 70 microns.

Figure 16 and 17 is depicted as the embodiment of some probe tips, and it has and an interior concentric external electrode of electrode.Each electrode is connected in power subsystem so that two electrodes can simultaneously or one after the other provide electric current to cornea.As an example, wish that beginning to apply electric power with interior electrode to cornea applies electric power with external electrode then, or apply electric power, only apply electric power then with external electrode with two electrodes.Suppose same current value, then interior electrode will apply electric power with the electric current density bigger than external electrode.This bipolar electrode makes electric current density and formation such as the waveform heat distribution that have nothing in common with each other of surgeon by changing electrode.

Probe 250 shown in Figure 16 have one with theintermediate layer 254 ofouter conducting layer 256 and insulant concentric in electrodes 252.In this preferred embodiment, the diameter ofinterior electrode 252 can be for 125 microns and from 150 microns of outerextension elongations.Outer 256 diameter can be 350 microns.Interior electrode 252 can by in theindentation insulating barrier 254 so thatinterior electrode 252 flush withexternal electrode 256, or can flush with stretch out fully between adjusting, or manual or by servo-control system.

Figure 17 illustrates another embodiment, and its middle probe 260 has an additional overcoat 262.Cover 262 has the internal channel 264 of an accommodating fluid.This fluid can be to make stable gas or the solution of higher resistance (for example distilled water) of electric current route that leads to cornea, and the latter provides coolant for eye.

Figure 18 illustrates the embodiment of dismountable probe 270 of an economy.Probe tip 270 has a steel wire 272, and it is positioned at a cabinet 274.Probe tip 270 has the part 276 of a flexibility, and it is preferably 45 from a main body 278 and stretches out.Preferably stretch out at an angle of 90 from gentle part 276 tip 280.What stretch out from the other end of handpiece 278 is a coupling 282.This joint 282 can have a conductive sleeve 284, and it inserts in the jack 286 of an internal probe socket 288.The end of steel wire 272 can be pressed between the outer surface of cover 284 inner surface and coupling 282 so that form between tip 280 and internal probe socket 288 and be electrically connected mutually.Cover 284 can have a fixture 290 so that probe tip 270 is fixed in the probe socket receptacle 288.Probe pinpoint end 280 can have the structure of the distal end shape that is similar to the tip shown in Figure 11,13,14,15,16 or 17.

Figure 19 illustrates a circuit 300, and it will prevent that probe tip from surpassing the useful life of regulation.Circuit 300 has a plurality of fuses 302, and it just is blown when probe is used to once-through operation.Probe is become can not reuse.Circuit 200 has 10-30 fuse 302 usually, thereby probe uses 10-30 time only.Circuit 300 (not shown) preferably are fixed on the printed circuit board (PCB) (not shown) that is installed on the probe.Each fuse 302 can be coated with flash of light inhibitor such as quartz sand, to prevent splashing/spraying of when fuse is blown fuse alloy.

In this preferred embodiment, fuse 302 is connected in driver 304, and it is connected in a plurality of shift registers 306 in parallel that are connected in series to.The clock plug (CLK) and the input plug D of first shift register are connected in unit 14.Unit 14 provides an input to first shift register at first, provides a series of pulses to make this input displacement by depositor 306 then on clock plug CLK.An effective output of one depositor 306 will start corresponding driving device 304 and select corresponding fuse 302.Unit 14 can be according to the time of the algorithm record that comprises in unitary hardware or the software by the record input of this shift register 306, and wherein each clock signal is equivalent to the end of once-through operation.As an example, have power, can produce a clock signal, and blow a fuse greater than 0.16W and persistent period four primary currents greater than 0.25 second.

Circuit 300 can have an independent sampling unit 308, and it is connected inunit 14 and fuse 302.Sampling unit 308 can have a photo-coupler 310, and it is isolation such asunit 14 and power surge, perhaps can be any voltage that is known in the art or the thresholding/comparator circuit system of electric current.Sampling unit 308 can have a relay 312, and it connects a switch in the time will sampling from each fuse 302.Sampling circuit 308 is sampled from each fuse 302 has be not blown with decision for how many fuses.The number of remaining fuse 302 can be provided by a display ofunit 14, and its number of times with the operation that can implement with this specific probe is relevant.As an example, after to each fuse sampling,unit 14 can show number 6, and this explanation can be implemented 6 operations again with probe.Show on the display that 0 explanation must the replacing probe.

For fuse 302 being sampled the time thatunit 14 is set to " sampling " with relay 312 and record passes through the input of depositor 306.If fuse 302 is blown when the output by depositor has started corresponding driving device 304, will start photo-coupler 310.If fuse 302 is blown, then will not start photo-coupler 310.Each fuse 302 is repeated the process of the output of this startup driver 304 and monitoring photo-coupler 310.Unit 14 calculates number about remaining feasible fuse with the remaining useful life of decision probe.

Figure 20 illustrates anotherprobe tip structure 350, andprobe tip 350 comprises aspring lever 352, and it stretches out from a handpiece 354.What stretch out fromhandpiece 354 equally is a male connector 356.Male connector 356 can be connected in the interpolation block of probe shown in Figure 18.Plug 356 can be replaced top 350 with anew unit.Handpiece 354 preferably has an outerplastic sheath 358, and it can be held by thesurgeon.Cover 358 is made of dielectric material, and it is isolated the surgeon with the electric current that flows throughprobe.Spring lever 352 also is coated with electrically insulating material usually.What be connected inspring lever 352 is atip supporting member 360.

As shown in Figure 21,tip supporting member 360 has one fromtip 362 that ablock 364 stretches out.Tip 362 can be one to extend the tip of the steel wire 366 in the spring lever 352.Steel wire 366 can be reinforced by the base portion 368 of an overstriking.Thicker steel wire part 368 can be into a stagewise single steel wire or a steel wire that inserts in the hollow pipe.A plurality of tip supporting member andtips 362 that are connected in asingle spring lever 352 can be arranged.

As shown in Figure 22, in the process of once-through operation,tip 362 is inserted in the cornea.The length attop 362 is generally the 300-600 micron, is preferably 400 microns, so that electrode enterssubstrate.Block 364 limits the penetrance of tip 362.The diameter oftip 362 is preferably 125 microns.The tip diameter is very little so that the invasion and attack to eye are minimized.

Power supply provides electric current bytip 362 to cornea.Electric current makes the substrate degeneration to correct the shape of cornea.Becausetip 362 is inserted into substrate, found that power is not more than 0.2 watt, persistent period and is not more than the optical correction that will enough make the tissue degeneratiaon of cornea in 1.0 seconds and form eye.The frequency of power between 1-20KHz, is preferably 4KHz usually.The deviation of the electrical characteristics by having reduced epithelial layer and outer corneal surface when corneas are inserted intip 362 has been improved to surpass probe has been placed repeatability when contacting with the surface of cornea.

In this preferred embodiment,spring lever 352 is 0.90 inch long and 0.05 inch diameter.The tip supporting member can be 0.25inch long.Tip 362 can have theembeding layer 370 of a dielectric material, and it stops electric current to flow throughepithelial layer.Tip 362 can be made of 302 stainless steel silks, and it stands the centerless grinding process.The steel wire that ground can make it stand chemical etching to form a cusp then.

Figure 23 illustrates another embodiment ofnapex 370, and whereinspring lever 372 has a plurality ofgrooves 374 to reduce the rigidity of bar 372.Figure 24 illustrates another embodiment of electrode 380, and it has the helical spring 382 between tip 384 and near-end386.As spring lever 352 and 372, tip 384 can be moved when the surgeon is pressed into cornea with electrode helical spring 382 in case the excessive insertion of tip 384.Figure 25 illustrates another embodiment ofelectrode 390, and it has thezigzag plane spring 392 betweentip 394 and near-end 396.

Figure 26 illustrates an embodiment of power supply 400, and it can provide electric power and the electric contact state of decision between electrode 402, cornea 404 and loop element 406.Electrode 402 can be connected in the electrode plug 408 of power supply 400.Loop element 406 can be connected in the loop plug 410 of power supply 400.

Electrode plug 408 and loop plug 410 can be connected in a current-voltage converter 412.Transducer 412 provides analog output voltage to analog/digital (A/D) transducer 414.The analog output voltage of electric pressure converter 412 is functions of a voltage drop between electrode plug 408 and the loop plug 410.Output voltage is also supplied with an impulse scaler 416.

A/D converter 414 and impulse scaler 416 can be connected in a controller 418.A/D converter 414 can provide the binary bit character string for controller 418, and its representative is from a magnitude of voltage of transducer 412.A/D converter 414 can comprise that a sampling and memory circuit are so that transducer 414 outputs are corresponding with the peak voltage that is provided by transducer 412.Impulse scaler 416 can provide a feedback signal so that indication flows to the electric energy of cornea 404 to controller 416.

Controller 418 can be connected in radio frequency (RF) pulse generator 420 and output switch 422.Pulse generator 420 can be a L-C circuit, and it responds a pulse of self-controller 418 to produce radio frequency (RF) waveform of a damping.Controller 418 can produce a series of pulses, and it produces the waveform of the damping of a series of supply corneas 404.As an example, each pulse can be 5 volts, one nanosecond pulse supplying with pulse generator 420.Controller 418 can realize that automatic gain control function is to increase or to reduce to supply with as feedback signal the amplitude of the pulse of pulse generator 420.For example, controller 418 can reduce amplitude for cornea and can increase amplitude to wet cornea.

Output switch 422 can switch between on-state and off state.Output forms a safety device when off state, and wherein electric power is not supplied with cornea 404.

Controller 418 can be connected on a DC power supply 424 and the display 426.Display 426 can comprise that a pair of indicating " wet " and the display lamp of " doing ".Controller 418 can also be connected to a power conditioning circuitry 428, a time regulating circuit 430 and a switch 432.Switch 432 can be foot switch or hand switch, and it can be by the program of surgeon's manipulation with start-up control device 418.Regulating circuit 428 and 430 makes the surgeon can change power level and the persistent period of supplying with electrode 402 respectively.

Controller 418 can be realized the software program according to the algorithm among Figure 27.Beginning, the surgeon is connected in cornea with loop element 404 and places electrode 402 and contacts withcornea tissue.In step 500, the surgeon closes switch 432, and it provides an input to controller 418.Controller 418 will enter a test program then.In test program, controller 418 provides a series of pulses so that produce a series of RF pulses instep 502 to pulse generator 420.Controller 418 also switches to switch 422 " being communicated with (on) " state so that pulse is passed to cornea 404 by electrode 402.

The part of the pulse that the number of pulses that provides in the process of test program normally provides in course of normal operation.For example, if power supply normally provides 4800 pulses in per 0.6 second to make corneal degeneration, then power supply 400 can provide 100 pulses in the process of test program.Total electric energy of low amount can be tested power supply to electrically contact and the electric energy that is enough to the appreciable impact cornea is not provided.

The RF pulse is by loop element 406 and loop plug 410 return voltage transducers 412.One is that voltage 412 and A/D 414 transducers of value by instep 504 of the function of the voltage on the loop plug 410 are supplied with controller 418.

Time rate of change and the corresponding resistance of magnitude of voltage that controller 418 can differential instep 506 be provided by A/D converter 414 to obtain voltage.Can adopt the voltage of differential, because ohmically slight variation will be provided because of the electric energy that provides in response to power supply tissue.Though described the voltage of differential, should be appreciated that controller 418 can utilize a for example voltage amplitude that does not have a differential of certain other voltage characteristic.Controller 418 can be with the magnitude of voltage and the Upper threshold contrast of the differential of reality then.

If the magnitude of voltage of differential is equal to or greater than Upper threshold, then controller 418 can produce a dried display output signal to start drieddisplay.In step 510, the dried display explanation cornea overdrying of startup.Controller 418 can also switch to off state with switch 422.

If actual value is lower than higher limit, then controller 418 can be with actual value and Lower Threshold contrast in step 512.If actual value is less than or equal to Lower Threshold, then controller can produce a wet display output signal to start wet display and to cut off switch 422 in step 514.If the voltage of actual differential is not less than threshold range, this test program will stop and can continue cornea is supplied with in pulse atstep 516 middle controller 418.The pulse of an interval is provided, and it will make corneal degeneration.

Wish to prevent that the tip from rotating to avoid any of cornea to tear with respect to handpiece.Figure 28 a-j illustrates other embodiment ofelectrode 500 near-ends, and it has anti-rotationstructure.Electrode 500 can insert in theopening 502 of handpiece 504.Figure 28 a illustrates theopening 502 that has a key 506, and it is matched with in thecorresponding groove 508 of electrode 500.The structure ofkey 506 and groove 508 prevents the rotation ofelectrode 500 with respect to handpiece 504.Perhaps,electrode 500 can have key 506 and handpiece can have groove 508.Figure 28 b illustrates one-touch structure in addition, and whereinhandpiece 504 andelectrode 500 have theplane surface 510 of coupling.

Figure 28 c-h illustrateshandpiece 504 and theelectrode 500 withannular opening 502, and the latter has different near-end shapes.Figure 28 c illustrates the near-end of squarely, and Figure 28 d illustrates triangle, and Figure 28 e illustrates elliptical shape, and Figure 28 f illustrates hexagonal configuration.Figure 28 g illustrates an electrode near-end, and it has a plurality of cam faces to prevent relatively rotating betweenelectrode 500 and the handpiece 504.Figure 28 h illustrates anelectrode 500 withspline 512.

Figure 28 i illustrates anelectrode 500 with a pair ofbar 514, and it can insert in a pair ofcorresponding opening 516 in handpiece 504.Perhaps,handpiece 504 can have twobars 514 andelectrode 500 can have two openings 516.Figure 28 j illustrates an embodiment, and wherein the opening of the near-end ofelectrode 500 andhandpiece 504 all has rectangular shape.

Figure 29 illustrates another embodiment of probe tip assembly 550.Probe tip assembly 550 comprises that a clamping probe 554 has arm 552.Probe 554 can comprise the electrode 556 that passes probe body 558 extensions.The near-end 560 of probe tip assembly arm 552 can be connected in the power supply (not shown).The near-end of electrode 556 can be connected in an equipment, and this equipment can be moved electrode 556 to the tip is exposed till the length of requirement.Then, electrode 556 can be connected in probe body by bending, welding or other modes.The far-end 562 of electrode 556 can have and is suitable for being placed on the tip that contacts with cornea.Handpiece 558 can be made of metal material, and its topical application has dielectric material such as paralene (paraffin), and the electric pathway of cornea top surface is led in its prevention.Probe body 558 can be crooked or be electrically connected on the electrode 556.

Probe body 558 can comprise a water jacket 564, and it is suitable for holding a card ball 566.Ball 566 can be biased in the groove 564 by a spring 568.Ball 566 can be positioned at the cover part 570 of arm 552.The internal channel 572 that probe body 558 can pass cover 570 extends.

Probe 554 can be changed by probe body 558 is pulled out internal channel 572.Inside groove 564 can have conical surface so that can release grooves 564 by card ball 566 at 570 o'clock handpiece 558 being pulled out cover.One new probe 554 can insert passage 572.Probe body 558 can have a block 574, and it limits the insertion depth of probe 554.

Figure 30 illustrates aprobe retainer 590, and it inserts shell for the probe shown in Figure 29 554 providesprotection.Retainer 590 can comprise acover 598, and it has aninternal channel 594 that is suitable for holding probe 554.Cover 598 can for example ABS (acrylonitrile/butadiene/styrene copolymer) or polyurethane constitute byplastics.Passage 594 can comprise eachfin 596 that clampsprobe.Retainer 590 can also have a knurledouter layer 598, and it makes the operator can more easily holdcover 592 and probe is pushed in the arm cover shown in Figure 29.

Figure 31 illustrates another embodiment of probeassembly 600.Assembly 600 comprises that one is connected in theprobe 602 of an arm 604.Probe 602 can comprise aninternal plug seat 606, and it holds amale connector 608 of arm 604.Jack 606 can comprise arecess 610, and it applies a pressure so thatprobe 602 is fixed on theplug 608.

Figure 32 illustrates an embodiment of probe 602.Probe 602 can comprise anelectrode 612, and itsinternal channel 614 that passesplastic sheath 616 extends.Thatelectrode 612 can be connected in is hollow, themetal rivet 618 in theinternal plug seat 606 shown inFigure 31.Electrode 612 can stick withglue agent 620 and be fixed on the cover 616.Adhesive 620 can be used ultraviolet light polymerization.Thetip 622 ofelectrode 612 can be stretched out from overlapping 616 end.

Figure 33 illustrate probe assembly 600 ' another embodiment, wherein electrode 612 ' pass cover 616 ' on eachhole 624 reel and in probe 602 ' interior formation " screw thread ".Electrode 612 ' sticking withglue agent 620 at steel wire is fixed in cover 616 ' later on and can passes 624 wirings of each hole.

Latch 608 ' can have acorresponding groove 626 with theelectrode 612 that holds screw-type '.This embodiment provides a probe, this probe have a dielectric overcoat 616 ', it has the contact screw thread of an inside, this screw thread provide one electrode tips and plug 608 ' between electric pathway.Dielectric overcoat 616 ' provide a protecting component for probe.

Figure 34 illustrates an embodiment of the handpiece 630 of probe 632 usefulness.Handpiece 630 can be connected in electrode 634, and handpiece 630 can be constituted and be had the outer surface 636 of a texture by a plastics molding and/or processing.The size and dimension that handpiece 630 has makes the surgeon refer to hold probe 632 with the pickpocket.

Though described some exemplary embodiment and be shown in all accompanying drawings, but should be appreciated that these embodiment only are illustrative rather than determinate to whole invention, and shown in the invention is not restricted to and concrete structure and the setting described, because for those those skilled in the art of this area, can expect various other remodeling.

Claims (8)

1. power supply that is used for the electrode tips of thermokeratoplasty, the indication that it can provide the electrical characteristics of cornea comprises:

One electrode plug;

One loop plug; And

One circuit, it can provide electric current to this electrode plug and cornea, and the indication of cornea electrical characteristics is provided, in response to the electric current that flows through cornea and this electrode and loop plug.

2. the described power supply of claim 1 is characterized in that, described electrical characteristics are functions of a voltage on the described loop plug.

3. the described power supply of claim 2 is characterized in that, described electrical characteristics are time rate of changes of the voltage on the described loop plug.

4. the described power supply of claim 1 is characterized in that, described circuit provides a series of radio frequency testing pulses to described electrode plug.

5. the described power supply of claim 3 is characterized in that, the number of radio frequency testing pulse is less than the number of radio frequency operation pulse.

6. the described power supply of claim 1, it is characterized in that, if described circuit provides wet these electrical characteristics of display output signal to be equal to or greater than a upper threshold then this circuit provides a dried display output signal if described electrical characteristics are equal to or less than threshold value.

7. the described power supply of claim 1 is characterized in that, if described electrical characteristics greater than Lower Threshold with less than Upper threshold, then described circuit provides the sequence of operations radio-frequency pulse.

8. the described power supply of claim 1 is characterized in that, described circuit changes the amplitude of the radio-frequency pulse of described operation according to electrical characteristics.

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